(1) Field of the Invention
The present invention relates to a surgical instrument and a method of using the instrument for tying surgical knots to close an incision or wound in body tissue. In particular, the present invention relates to an elongate instrument that in conjunction with surgical forceps is used to tie suture knots during surgical procedures that are performed inside the body in areas of limited access. Medical procedures that do not require the body part being repaired to be completely opened are being performed with ever increasing frequency. For example, laparoscopy is now frequently used for gallbladder, and other surgeries, operating through small puncture wounds. Because the entry wound that is used to access the surgery area is very small, the cutting and separating of various tissue layers to expose intra abdominal organs is not required. One of the most profound benefits from this type of procedure is that rehabilitation periods are considerably shorter in comparison with traditional fully invasive surgery. During the laparoscopic procedure, the damaged body tissue is repaired by suture knots that must be tied in confined areas inside the abdomen. Often, it is difficult to tie the knots so that they are centered on the incision or wound being repaired. However, it is important that the knots are properly tied to ensure that the tissue sections being joined are drawn together in a uniform manner. This promotes healing by ensuring that the joined tissue will mend with a limited amount of hemorrhaging.
(2) Prior Art
The prior art has described various types of suturing tools used from a remote location outside of the body, to manipulate a needle connected to a length of suture thread, to close a wound or incision inside a body cavity. The prior art suturing tools require that the access opening into the body be only as large as a puncture wound. Surgical tools including the needle and suture are then introduced into the body cavity through the puncture wound to perform the suturing procedure. However, the limited access into the body cavity provided by the puncture wounds makes it difficult to manipulate the suturing tools to center the suture knot on the wound being closed. Illustrative of the prior art is U.S. Pat. Nos. 3,871,379 to Clarke; 4,597,390 to Mulhollan et al; 4,602,635 to Mulhollan et al and 4,683,885 to Hutterer et al.
Clarke describes three surgical instruments and a method for suturing and ligation. The first instrument is a combined needle and forceps and is comprised of an elongated parallelogram type of linkage, which is suitable for insertion through a first cannula. A needle is mounted on a working end of one of the links. The needle is moveable from a position substantially aligned with the linkage to a position transverse to the linkage. A handle, at an opposite end of the linkage, enables a surgeon to move the needle for sewing sutures inside the body. The second instrument is a combined forceps, suture guide and cutter and has an elongated parallelogram type of linkage, which is suitable for insertion through a second cannula. The working end of the linkage is provided with moveable jaws that can be actuated as forceps. The jaws have an associated groove that serves as a suture guide for receiving a suture. The jaws also have opposed cutting blades for cutting sutures. A third instrument comprises a ligator having an elongated stem with a suture guide at one end for guiding a suture through a cannula. These three instruments enable a surgeon or physician to sew a suture into body tissue located in an area of limited access inside the body while working the combined needle and forceps instrument from a remote location, outside of the body. After the suture is sewn into the body tissue, the suture is pulled out of the body, through one of the cannulas, and a knot is tied in the suture. The knot is then slid down the suture to the body tissue being sewn by the ligator instrument. Finally, the suture thread is cut by the cutter blades of the second instrument to complete a surgical suture. These instruments are particularly adapted for laparoscopic surgical procedures.
Mulhollan et al describes two types of surgical instruments for suturing body tissue from a remote location, outside of the body. U.S. Pat. No. 4,597,390 describes a surgical tool for manipulating a needle that has been set in tissue. The surgical tool comprises a tube with a telescoping rod mounted inside of the tube. The tube and rod have a diametrical slot in one end that forms a bifurcated slot. The tube and rod are relatively rotatable so that slot portions in the tube are moveable in and out of alignment with the slot in the rod. When the slot portions are in alignment, the shank of the needle can be received in the slots, and as the slots are moved out of alignment, the needle is gripped by the side walls of the slots. With the needle gripped by the slots, the surgical tool can be manipulated to begin a stitch through the body tissue. Diametrical holes in the tube and rod are also provided and form a bifurcated passage for gripping the top of the needle. That way, the needle can be pulled through the body tissue to complete the stitch. This surgical tool is not useful for centering a suture knot on an incision. U.S. Pat. No. 4,602,635 describes a remote surgical knot tier tool and method for its use. The knot tier tool can be used to tie a knot in suture thread in a remote manipulation area and for pushing and placing the knot into a surgical site in the body of a human being, or an animal through a puncture wound or other small opening. However, pushing the knot into the body tissue does not ensure that the knot will be evenly centered on the body tissue. Thus, the body tissue may not be pulled together evenly, which tends to retard proper mending of the tissue.
Hutterer et al describes a method for tying a double-looped knot in suture thread using an applicator in combination with an endoscopic tube. The applicator is comprised of a coil connected to a longitudinal passage through a shaft. The applicator has hollow turns connected to the shaft passage for reception of the suture thread. The suture thread is passed through a loop projecting from a radial opening at a distal extremity of the shaft. The thread is then drawn through the shaft passage and fastened to the proximal end of the shaft. Tying the single stitch after piercing the tissue is done by passing the needle axially through the coil and then around the thread and twisting the coil out of the loop formed thereby to form the first half of a knot. The knot is then completed by a second half of the knot, which is tied in the same way. The two halves of the knot are then pulled together. However, it is not certain that the knot will be properly centered on the body tissue being sewn. If not, the two halves of the body tissue may not be brought together properly, which retards the mending process.
Other prior art that is less relevant to the present invention includes U.S. Pat. Nos. 2,416,260 to Karle; 2,689,147 to Smalley; and 2,895,478 to Post.
What is not shown by the prior art is a surgical tool that is useful in surgery procedures for centering a suture knot on a wound in body tissue of limited accessibility and that can be manipulated from an area of accessibility, outside the body. If the body tissue is to mend properly, it is important that the suture knot be centered on the wound to join the tissue together in a uniform manner.